$add = 0
$subs = 0
$loc = 0

git log --author="2980439042" --pretty=tformat: --numstat | ForEach-Object {
    $fields = $_ -split '\s+'
    if ($fields.Length -eq 3) {
        $add += [int]$fields[0]
        $subs += [int]$fields[1]
        $loc += [int]($fields[0] - $fields[1])
    }
}

$total = $add + $subs
Write-Host "added lines: $add, removed lines: $subs, total lines: $loc"
git shortlog --all --numbered --summary --no-merges

